Structure-Composition-Property Relationships in Complex Intermetallic Phases: Experimental and Theoretical Studies

复杂金属间相的结构-成分-性能关系：实验和理论研究

• 批准号: 0241092
• 负责人: Gordon Miller
• 金额: $ 39万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-02-01 至 2007-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0241092&HistoricalAwards=false
• 关键词: Structure; Composition; Property; Relationships; Complex

This project involves combining experimental and theoretical approaches to search for and study new complex intermetallic compounds that will have interesting structural and magnetic properties with possible applications to environmentally friendly refrigerants and magnetic sensors. The compounds targeted consist of active metals (sodium, potassium, strontium, barium, and rare-earths) with combinations of magnetic elements (iron, cobalt, nickel) and the post-transition elements (aluminium, germanium, indium, silicon and germanium): such compounds should adopt beautifully complex structures involving metal clusters that are controlled by optimizing metal-metal bonding, but also showing arrangements giving interesting magnetic properties through exchange interactions coupled to their orbital overlaps, i.e., magnetocaloric effects and magnetostriction. These studies will lead to fundamental understanding of how intermetallic compounds form and the factors that control structure in magnetic systems. If we are successful to optimize the magnetocaloric effect, we may find a material effective for refrigeration near room temperature that is environmentally benign and economically feasible. Young scientists will learn state-of-the-art techniques in air-sensitive, high temperature synthesis, diffraction and in the theoretical calculation of electronic This project is designed to form and study new compounds between different metallic elements, called intermetallic compounds. One component of these new compounds will be magnetic elements, like iron or cobalt, which will allow us to probe new compounds to serve as materials for refrigeration in place of chlorofluorocarbons ("magnetic refrigeration"). Such compounds use magnetism to perform refrigeration, which is a more efficient process and the materials are also more environmentally friendly than current substances. An important fundamental goal of this research is to understand what factors control the formation and growth of intermetallic compounds, so that we may ultimately be able to design materials with specific electrical or magnetic properties. We plan to achieve this goal by searching for new intermetallic compounds through careful synthesis, through measurement of the structure and arrangement of elements in their crystals, through determination of their magnetic properties and through computer modeling. Students involved with this project will learn state-of-the-art techniques in metals synthesis, characterization and theoretical modeling. This project, which combines experimental and theoretical work, will prepare these students for careers in academia (for training our next generation of scientists and engineers) or in industry (where they can apply new techniques for the fabrication of new materials).

该项目涉及结合实验和理论方法，以搜索和研究新的复杂的金属间化合物，这些化合物将具有有趣的结构和磁性特性以及可能应用于环保的制冷剂和磁性传感器。 靶向的化合物由活性金（钠，钾，锶，钡和稀土分子）与磁元素（铁，钴，镍）和后转换元件的组合组合组合而成通过交换相互作用与轨道重叠相结合的有趣磁性特性，即磁化效应和磁曲折。 这些研究将导致对金属间化合物如何形成的基本了解以及控制磁系统中结构的因素。如果我们成功地优化了磁联性效应，我们可能会发现在室温附近制冷的材料在环境上是良性且在经济上可行的。 年轻的科学家将学习在空气敏感，高温合成，衍射和电子的理论计算中，该项目旨在形成和研究不同金属元素之间的新化合物，称为金属间化合物，称为金属间化合物。 这些新化合物的一个组成部分将是磁元素，例如铁或钴，这将使我们能够探测新的化合物作为制冷材料，代替氯氟化碳（“磁制冷”）。 这样的化合物使用磁性进行制冷，这是一个更有效的过程，材料也比目前的物质更环保。 这项研究的一个重要基本目标是了解哪些因素控制金属间化合物的形成和生长，以便我们最终能够使用特定的电气或磁性设计材料。 我们计划通过仔细合成，通过测量晶体中元素的结构和排列，通过确定其磁性和计算机建模来搜索新的金属间化合物来实现这一目标。 参与该项目的学生将学习金属合成，表征和理论建模的最先进技术。 结合了实验和理论工作的该项目将使这些学生在学术界（培训我们的下一代科学家和工程师）或行业（他们可以在制造新材料的制造中应用新技术）做好准备。